[Malcolm] finally got fed up with the fumes produced by his 3D printer, so he decided to setup this rather extensive fume exhausting system.
He already has a pretty awesome setup with his Type A 3D printer inside of a filing cabinet, with a plastic tote above it to keep his filament from absorbing too much water. But as you know, the fumes released while printing ABS are actually pretty bad for you. With this in mind he 3D printed adapter rings and fitted a fan salvaged from a space heater to the outside of his filing cabinet. A dimmer switch provides variable fan speeds and some dryer vent tubing reroutes the fumes to central vac piping which then goes directly outside. When the system is not in use the piping can be plugged to prevent cold air from entering the house. It’s a fairly clean build but [Malcolm] wants to make a nicer enclosure for the fan and speed control circuit.
The major problem we see with doing something like this is removing too much heat from the build chamber which can always affect print quality. Do you vent your 3D printer?
I’ve been thinking about this for when my printer works, I would turn on the fan once the print is finished so it wouldn’t affect the temperature while printing, then you can run the fan less (hopefully).
I don’t vent, but I do have it enclosed in a plexi box, which mitigates the fumage somewhat, and, allegedly, is a Stratasys patent violation: http://www.thingiverse.com/thing:55065. It’s in an unheated space, so I made a preheater out of a 75W light bulb and a coffee can shade/radiator. When I’m done, I typically just open it up and evacuate to the house.
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allegedly, is a Stratasys patent violation:
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Which shows how ignorant the patent reviewers are. There is a plethera of prior art regarding enclosures that keep things warm, the most prominant, used, long standing and well known being a building.
It’s as rediculouse as the single click patent that was issued years ago.
There is nothing wrong with issueing a patent that protects an inventor for a short time so that he can earn back the research and development costs that went into the invention. There is however, a great deal wrong with the educated idiots that are hired to review patent applications.
What about running the exhaust through a respiratory mask organic vapor filter cartridge, or activated carbon?
After many builds with carbon filters and P95 respirator filters that didn’t work I went this route.
In school I was tought that it is never wise to connect a dimmer switch to an electric motor. Of course, the example given at the time was a wall mounted switch connected to a ceiling fan, but none-the-less I would not leave that unsupervised during operation.
Admittedly I’m old and out of practice, but there are safer methods.
Generic dimmers do not like inductive loads, no transformers, fluorescents, etc, and you really shouldn’t run motors off them but you can usually get away with it. There are dimmers for fans though, they are more expensive than the typical light dimmer.
Worst thing that will happen is the triac inside will fry.
Yeah an “inductive” dimmer probably has flyback diodes in it. I guess putting those diodes in is expensive. Because just the diodes themselves sure aren’t. Oddly a lot of AC dimmers actually use SCRs.
Ya in this build I used a dimmer switch that states the following “General purpose ceiling or paddle fan controller”
No, dimmers rated for inductive duty still have triacs but they are more accurately controlled. In a typical dimmer circuit there is a pot that divided the line voltage to a diac. The diac is connected to the gate of the triac, when the voltage gets high enough the diac conducts and the triac fires. The triggering can be kind of random. On an inductive dimmer they use a phase angle IC or a microcontroller to control the firing of the switching device. Considerably higher and more expensive part count.
Why? If for the environments sake, would the ABS fumes really do more damage to the environment than the amount of energy required to manufacture and ship a respirator cartridge?
I meant for this to be a reply to RandyKC but apparently forgot to click reply.
I assume he meant filtering the air instead of pumping it outside.
I assumed this as well, but wouldnt the resources, energy and pollution caused from the manufacture of the filter outweigh whatever minor harm to the environment would be caused by the ABS fumes?
I was thinking of filtering the air inside. If the printer was enclosed it would only need to be filtered before opening the printer and the time it would be used would be relatively short. There would be less heat lost and you would be addressing the problem of removing the fumes rather than diluting them. It might help if more than one stage was used (ionic, filter, carbon, etc).
Just thinking that venting to the outside isn’t always an option or responsible.
Would ABS be absorbed by bubble-filtering?
What about instead of a fan at the vent, have slight positive pressure in a line, and add a heater to that, and have an exahust tube. It would push some fumes out into the room, but a reasonably airtight box with a big enough exit port should reduce the effect significantly. It might help keep a warmer printer, as all the air coming in would pass over the heater, instead of having to heat it once it has already entered.
Just an idea.
Could you not just vent in heated air to replace the stink hot air you vent out?
To solve the heat-loss problem, just use an air-to-air heat-exchanger, so the incoming fresh air is heated by the exhaust. Although I haven’t done it, it seems relatively easy to build using thin sheet metal, e.g. aluminum roof flashing.
With an enclosed box, it is only necessary to move a tiny amount of air to control the stink. Most fans can’t go down this small of a draught. A tiny turbine might work, blade fans are so leaky at moving a small but positive air displacement through a duct and against building and wind draughts. One thing that can do it is a player piano air motor in an inclosed box of it’s own which is suction of a metered amount per rev of the shaft. Speed up before opening.
Hack! It would be easy to make two little exausters driven from a slow motor to pump out the bad air.
Also try those air inflators for mattress, they’re at Aldi’s. DC and easily dimmed. Low CFM and some positive action against said building and wind effects.
I built the heat exchanger (HRV) you guys need already.
Using it to recover heat from my soldering fume hood.
https://www.youtube.com/watch?v=4FSewTEsGD8&feature=c4-overview&list=UUyWbbmuQVZo6ALU_HMsesvg
Works fantastic.
Submitted it to Hack A Day yesterday.
I use a hepa filter on high in my little office and have noticed a pretty decent change. I am also running a replicator 2x so it is mostly enclosed. I dont have any tubes or hoses running to and from the printer I just make sure I have the filter running on high, and just for the sake of having it, the ionizer turned on as well.
Whynot instead of plugging the vacuum pipe when not in use, install a check valve type flap like whats used in bathroom exhaust vents..